Reliability still in doubt

Brain scans are being
used experimentally for everything from testing political leanings to
determining whether a prisoner is a psychopath to lie detection. Now, for the
third time in a year, a major study has been published questioning their reliability.
The analysis, which has been accepted for publication
in Annals of the New York Academy of Science, questions studies
which have reported 80 or 90% correlations between specific regions of brain
activity and personality traits and emotions.

After reviewing 63 journal articles which
described studies using functional magnetic resonance imaging in which tests
had been performed twice on the same people at different times, the authors
conclude that, on average, there is only a 50% correlation between the brain
regions that light up in the first and second tests in the same person.

“The thrust of our experiment is that
it challenges the assumptions of how reliable the results from any one fMRI
study may be,” says Craig Bennett, a postdoctoral researcher in cognitive
neuroscience at the University of California, Santa Barbara. “The end
question we want to know is: if you did your experiment again, would the
results — and the conclusions — be the same?” ~ Nature
News, Mar 17

Michael Cook
brain scans
fMRI